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Novel Representation of Leaf Phenology Improves Simulation of Amazonian Evergreen Forest Photosynthesis in a Land Surface Model
Full text linkLeaf phenology in the humid tropics largely regulates the seasonality of forest carbon and water exchange. However, it is inadequately represented in most global land surface models due to limited understanding of its controls. Based on intensive field studies at four Amazonian evergreen forests, we propose a novel, quantitative representation of tropical forest leaf phenology, which links multiple environmental variables with the seasonality of new leaf production and old leaf litterfall. The new phenology simulates higher rates of leaf turnover (new leaves replacing old leaves) in dry seasons with more sunlight, which is then implemented in ORCHIDEE, together with recent findings of ontogeny-associated photosynthetic capacity, and is evaluated against ground-based measurements of leaf phenology (canopy leaf area index and litterfall), eddy covariance fluxes (photosynthesis and latent heat), and carbon allocations from field observations. Results show the periodical cycles of solar radiation and vapor pressure deficit are the two most important environmental variables that are empirically related to new leaf production and old leaf abscission in tropical evergreen forests. The model with new representation of leaf phenology captures the seasonality of canopy photosynthesis at three out of four sites, as well as the seasonality of litterfall, latent heat, and light use efficiency of photosynthesis at all tested sites, and improves the seasonality of carbon allocations to leaves, roots, and sapwoods. This study advances understanding of the environmental controls on tropical leaf phenology and offers an improved modeling tool for gridded simulations of interannual CO2 and water fluxes in the tropics. ©2019. The Authors
Diferenças inter e intrassexuais na aprendizagem espacial de um peixe amazônico sexualmente dimórfico
Full text linkThe individual processes of acquisition, retention and use of information to solve cognitive tasks can vary between individuals. Such cognitive variation may be explained by consistent behavioral differences, resulting from sexual dimorphism or morphological variations within a single sex. This can generate different susceptibilities to predation in individuals with higher degree of ornamentation, and/or mating preference for individuals with enhanced cognitive skills, which contributes to the evolution of cognition. In that context, when selective pressures act differently among individuals, variations in ecologically relevant decision-making are expected. Additionally, a functional link between individual cognitive variation and animal personality is suggested, generating speed-accuracy trade-offs. In a further step, we investigated the relationship between spatial learning to male ornamental degree and neophobia and finally female mate choice, in the Amazonian fish Crenuchus spilurus, a sexually dimorphic species. We found no sex differences in the learning rate of the spatial task. However, when assessing males’s individual differences, those with higher degree of ornamentation showed better performance in the learning task, displaying greater precision to solve the maze on the last day of test. The performance of these males was better than males with lower degree of ornamentation and females. Males with a higher degree of ornamentation were more neophobic and took longer to resolve the spatial task on the first attempt. This suggests that males with a higher degree of ornamentation behave according to the asset-protection principle, which proposes that more attractive males should be more cautious as a result of higher future returns consequences of their physical characteristics. In addition, females showed preference for males with higher degree of ornamentation, which consequently, were also the individuals who showed better performance in learning the spatial task. We propose that the sex differences in cognition can emerge from the intrassexual variation, caused by the selective pressure that occurs in males with higher degree of ornamentation. Additionally, as the asset-protection principle stems from the pressure of predation, sexual selection through female mate choice provides an exchange of rewards and risks, on which natural selection acts indirectly by increasing learning skills.Os processos individuais de adquirir, armazenar e usar informações para resolver tarefas cognitivas podem variar entre os indivíduos de uma mesma espécie. Isso ocorre, por exemplo, quando existem variações comportamentais consistentes, decorrentes de dimorfismo sexual ou por variações morfológicas dentro de um único sexo. Isso pode gerar diferentes suscetibilidades à predação em indivíduos mais ornamentados, ou preferência por indivíduos com melhores habilidades cognitivas, o que contribui para a evolução da cognição. Nesse contexto, quando pressões seletivas atuam de maneira distinta entre os indivíduos, é esperado o surgimento de variações na tomada de decisões ecologicamente relevantes. Adicionalmente, é sugerida uma ligação funcional entre a variação individual cognitiva e a personalidade animal, gerando demandas conflitantes entre precisão e velocidade de decisão. Neste estudo, investigamos a neofobia, o aprendizado espacial e a escolha feminina no peixe amazônico Crenuchus spilurus, uma espécie sexualmente dimórfica. Não encontramos diferença sexual na taxa de aprendizagem da tarefa espacial. Contudo, quando avaliadas as diferenças intrassexuais, machos mais ornamentados mostraram melhor desempenho na tarefa, apresentando maior precisão para resolver o labirinto no último dia de testes do que machos menos ornamentados e fêmeas em geral. Machos mais ornamentados são mais neofóbicos e levaram mais tempo para resolver a tarefa espacial na primeira tentativa. Isso sugere que esses machos se comportam de acordo com o princípio de proteção de ativos, quando machos mais atraentes devem ser mais cautelosos como resultado de maiores retornos futuros decorrentes de suas características físicas. Além disso, fêmeas mostraram preferência por machos mais ornamentados, que foram os indivíduos que apresentaram melhor desempenho na tarefa espacial. Com estes resultados, propomos que a diferença sexual na cognição pode emergir da variação intrassexual, causada pela pressão seletiva que ocorre sobre machos mais ornamentados. Adicionalmente, como o princípio de proteção de ativos decorre da pressão de predação, a seleção sexual por meio da escolha feminina proporciona uma troca de recompensas e riscos, sobre a qual a seleção natural atua indiretamente aumentando habilidades de aprendizado
A Guide to Carrying Out a Phylogenomic Target Sequence Capture Project
Full text linkHigh-throughput DNA sequencing techniques enable time- and cost-effective sequencing of large portions of the genome. Instead of sequencing and annotating whole genomes, many phylogenetic studies focus sequencing effort on large sets of pre-selected loci, which further reduces costs and bioinformatic challenges while increasing coverage. One common approach that enriches loci before sequencing is often referred to as target sequence capture. This technique has been shown to be applicable to phylogenetic studies of greatly varying evolutionary depth. Moreover, it has proven to produce powerful, large multi-locus DNA sequence datasets suitable for phylogenetic analyses. However, target capture requires careful considerations, which may greatly affect the success of experiments. Here we provide a simple flowchart for designing phylogenomic target capture experiments. We discuss necessary decisions from the identification of target loci to the final bioinformatic processing of sequence data. We outline challenges and solutions related to the taxonomic scope, sample quality, and available genomic resources of target capture projects. We hope this review will serve as a useful roadmap for designing and carrying out successful phylogenetic target capture studies. © Copyright © 2020 Andermann, Torres Jiménez, Matos-Maraví, Batista, Blanco-Pastor, Gustafsson, Kistler, Liberal, Oxelman, Bacon and Antonelli
Libélulas do oeste de Minas Gerais, Brasil: Lista de espécies e novos registros
Full text linkThe knowledge about the richness and distribution of Brazilian dragonflies is still being unveiled. Over the years, inventories, reviews, and descriptions have been made. These contributions, apart from the taxonomic value, also provide valuable data on the occurrence of species and their distributions, which are rarely accompanied by notes about natural history and behavior. Keeping this legacy in mind, we collected dragonflies between 2011 and 2019 in Minas Gerais state, which resulted in the registration of 90 species, 41 genera and 11 families. Our results also increase distribution data, an important tool for conservation actions, and provide additional information about habitat and biology of species. © 2020, Universidade Estadual de Campinas UNICAMP. All rights reserved
Comments on the Classification of Neotropical Scionini (Tabanidae) with a Description of a New Genus
No full textThe classification of the Tabanidae had remained stable over the last 60 years after Mackerras proposed a great revolution in the arrangement of the family. Recently, some new proposals based on molecular data have once again changed the classification of the family, mainly with a focus on the tribe Scionini. The present paper introduces a critical analysis based on the taxonomical view of the recent proposed classification of Scionini. Three genera are discussed: Lepmia Fairchild, Parosca Enderlein, and Pseudoscione Lutz. Lepmia atra (Philippi), L. grisea (Jaennicke), and L. leucothorax (Ricardo) are transferred to a new genus, Sixtomyiagen.n., based on its morphological differences from Lepmia. Other three species receive a new combination: Parosca subulipalpis (Enderlein) n. comb., Pseudoscione albifrons (Macquart) n. comb., Ps. hibernus (Wilkerson & Coscarón) n. comb. A key to species of Sixtomyia is provided and diagnostic characters are illustrated. © 2020, Sociedade Entomológica do Brasil
Description of the immature stages of the Neotropical whirligig beetle Gyrinus (Neogyrinus) rozei Ochs, 1953 (Coleoptera: Gyrinidae) and first report of the parasitoid wasp Melanosmicra sp. (Hymenoptera: Chalcididae) on a Gyrinus species
No full textIn most species of Gyrinidae, the immature stages are unknown, especially due to the difficulty in collecting the juveniles and assigning them to a particular species. Molecular association is a feasible technique that may solve this problem. Recent studies have used DNA sequence data, specifically the gene cytochrome oxidase subunit I (COI), to associate immature and adult stages, thus enabling the description of the former. The objectives of this study were (1) to describe and illustrate the immature stages of Gyrinus (Neogyrinus) rozei Ochs, 1953 including morphometric, chaetotaxic and bionomic information, and (2) to assess the usefulness of the gene COI to associate immatures and adults of Gyrinus. The studied specimens were collected in Roraima state, northern Brazil. The association of immature and adult stages was done either by rearing adults under laboratory conditions or by using DNA sequence data (COI). Eggs were described based on scanning electron microscopy; they are distinguished mainly by several features of chorion, micropyle and reticulation. Larvae of G. (N.) rozei can be distinguished from those of other Neotropical Gyrinidae by a combination of several characters, including the stipes with five robust hook-like additional setae on the dorsointernal margin, and the lacinia roughly hook-shaped. The pupa is similar to that of G. argentinus Steinhel, 1869, except for the number of setae on the body. The first record of the parasitoid wasp Melanosmicra sp. (Hymenoptera: Chalcididae) on a Gyrinus species is also provided. Copyright © 2020 Magnolia Press
A new genus of chevron cricket (Orthoptera: Anostostomatidae: Lutosinae) from the Colombian and Venezuelan Amazon Rainforest
No full textTintiyakus gen. nov., is described based on specimens from the Amazon region, including three species: Tintiyakus piaroa n. comb. (transferred from Hydrolutus Issa & Jaffe), Tintiyakus sexangulus sp. nov. (type-species pres. desig.) and Tintiyakus trewicki sp. nov. After Hydrolutos, this is the second anostostomatid genus described to be known from its semiaquatic behaviors, inhabiting the lowlands of the Amazon rainforest. An identification key for species based on males is provided. © 2020 Magnolia Press
How will farmed populations of freshwater fsh deal with the extreme climate scenario in 2100? Transcriptional responses of Colossoma macropomum from two Brazilian climate regions
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